Cylinder lock



l Aug. 31, 1965 M. M. CHECK E'r-AL CYLINDER LOCK Filed Feb. 8, 1965 lNvENToRi A TTDP/Yfy United States Patent O 3,203,210 CYLINDER LCK Mathias M. Check, Stratford, and Paul l?. Rubik, Ambler, Pa., assignors, by mesne assignments, to Yale it Towne, Inc., New York, NX., a company of hio Filed Feb. 8, 1963, Ser. No. 257,281 11 Claims. (Cl. 70-340) This invention relates to a lock of the type having two key operated cylinders, either of which when operated, is effective to operate the latch mechanism of the lock to retract a bolt.

Such an arrangement permits master keying of a series of locks by having one cylinder of each lock of the series operable by the same key and the other cylinders of the locks of the series operable by different keys.

In locks of this type, the key plug of each cylinder, when in the locked condition, is operatively disconnected from the latch operating mechanism.

With locks of this type as heretofore proposed, it is possible to pick the lock, without rotating the key plug, by inserting a picking tool through the key slot to engage the latch operating mechanism and then rotating the picking tool to operate the latch operating mechanism to retract the bolt of the lock.

This invention provides a lock construction of this general type which cannot be picked in this manner, and which at the same time, is of simple, inexpensive, compact construction.

Other objects and a-dvantages of the invention will become apparent from the following description, when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a front view of a lock constructed in accordance with the invention, showing the lock mounted in a door knob;

FIG. 2 is a sectional View taken along the line 2--2 of FIG. 1, showing a key inserted in one of the cylinders of the lock;

FIG. 3 is a slightly enlarged sectional view of the lock shown in FIG. 2, showing a key inserted in the other cyl-4 inder of the lock;

FIG. 4 is a sectional view taken along the line 4 4 of FIG. 2; and

FIG. 5 is a perspective view of two meshing gears forming a part of the latch operating mechanism.

Referring to 1FIGS. 1 and 2, a lock 10, constructed in accordance with the invention, is shown mounted in the end of a knob 11. The lock includes a housing 12 having a pair of parallel, cylindrical bores 13 and 14 extending therethrough. A key plug 15, having a key slot 16, is mounted for rotation in the bore 13, and a key plug 17, having a key slot 18, is mounted for rotation in the bore 14.

Key plug 15 is normally held against rotation in the well known maner by tumblers 19, shown in FIG. l, and key plug 17 is normally held against rotation by tumblers 20. Insertion of a key of the proper bitting in the key slot 16 of the key plug 15 sets the tumblers 19 to permit rotation of the key plug 15, while insertion of a key of the proper bitting in the key plug 17 sets the tumblers 20 to permit the key plug 17 to be rotated.

The key plug 15 has an inner end portion 21 of reduced diameter, and the key plug 17 has an inner end portion 22 of reduced diameter. The key slot 16 extends through the reduced end portion 21 of the key plug 15, and the key slot 18 extends through the reduced end portion 22 of the key plug 17. A member 23, having external gear teeth 24, is mounted for free rotation on the inner end portion 21 of the key plug 15, and a similar member 25, having external gear teeth 26 which mesh with the gear teeth 24 oi the member 23, is mounted for free rotation ICC on the iner end portion 22 of the key plug 17. The member 23 has an internal groove 27 formed therein providing an inturned flange 28, and the member 25 has an internal groove 29 providing a flange 30. A pin 31 extends through the end portion 21 into the groove 27 of the member 23, as best shown in FIG. 4, thereby holding the member 23 against endwise removal from the end portion 21 of the key plug 15, while allowing free rotation of the member 23 relatively to the key plug 15. The member 23 is of slightly larger diameter than the cylindrical bore 13, and when connected to the inner end portion 21 of the key plug 15 by the pin 31, retains the key plug 15 within the cylinder 13.

In a similar maner, a pin 32 extends through the inner end portion 22 of the key plug 17 into the groove 29 of the member 25, thereby connecting the member 25 to the end portion 22, so that the member 2S retains the key plug 17 within the cylindrical bore 14.

In assembling the lock, the pins 31 and 32 are lirst inserted through the reduced end portions 21 and 22 of the key plugs 15 and 17 and the key plugs then inserted in the bores 13 and 14 of the housing 12. The members 23 and 25 are next slipped over the reduced end portions 21 and 22. This is made possible by the provision of diametrically opposed slots 33 and 34 through the flanges 28 and 30 of the members 23 and 25, which permit the pins 31 and 32 to pass into the grooves 27 and 29 of the members 23 and 25, as the members 23 and 25 are slipped over the end portions 21 and 22. Thereafter, the members 23 and 25 are rotated relatively to the end portions 21 and 22 until the slots 33 and 34 are aligned with the key slots 16 and 18. In this position of the members 23 and 25, the pins 31 and 32 are positioned behind the fianges 28 and 30 to connect the members 23 and 25 to the reduced end portions 21 and 22. During normal operation of the lock, the pins 31 and 32 do not again become aligned with the slots 33 and 34, so that the members 23 and 25 remain ellectively connected to the reduced end portions 21 and 22.

A back plate 35 is next secured to the inner end of the housing 12 by means of screws 36, or other means, and the assembled lock 10 then inserted in the knob 11. When the lock assembly 10 is inserted in the knob 11, a hub 37 secured to the back plate 35 extends through an opening 38 in an internal flange 39 of the knob and the lock assembly 10 is held in the knob by a snap ring 40 which seats in a groove in the hub 37 and engages the surface of the ange 39 surrounding the opening 38.

The members 23 and 25 form parts of the latch operating mechanism and to this end, an operating bar 41, or other suitable adapter, is pivotally connected by means of a pin 42 to clevis members 43 which are secured to the member 25. The operating bar 41 is operably connected in the well-known manner to a bolt (not shown) of the lock, so that rotation of the operating bar 41 re tracts the bolt. Thus rotation of either the member 25 or the member 23 serves to rotate the operating bar 41 to retract the bolt or otherwise operate a bolt controlling mechanism.

When a key, such as shown at 44 in FIG. 2, is inserted in the key slot 18 of the key plug 17 to set the tumblers 20 thereof and permit rotation of the key plug by the key, the inner end portion 44a of the key extends into one of the slots 34 in the flange 30 of the member 25, as shown in FIG. 2, thereby connecting the member 25 to the key plug. Rotation of the key plug 17 thereafter by the key 44, therefore, rotates the member 25 and the operating bar 41, connected thereto, to retract the bolt. At this time, the member 23 is free to rotate on the inner end portion 21 of the key plug 16, so tha-t the member 23 has no effect on the rotation of the member 25.

If a key, such as shown at 45 in FIG. 3, is inserted in the key slot 16 of the key plug 15 to set the tumblers thereof and permit rotation of the key plug 15, the inner end portion 45a of the key engages in the slot 33 of the member 23 to connect member 23 to the key plug 15, Rotation of the key plug by the key 45 then serves to rotate the member 23. This rotation of member 23 is transmitted to the member 25 through the meshing gear teeth 24 and 26 so that the member 25 and the operating bar 41 are rotated to retract the bolt.

It will be noted that the slots 33 and 34 in the members 23 and 25 are off centered relatively to the axes of rotation X-X and Y-Y of the key plugs 15 and 17 and that the reduced end portions 21 and 22 extend over the slots 33 and 34 in the members 23 and 25, so that the only access to the slots 33 and 34 is directly from the key slots 16 and 18. Because of this, it is impossible to rotate the members 23 or 25 by a tool inserted through a key slot of the key plugs, except by simultaneous rotation of the key plugs. Thus picking of the lock through rotation of the members 23 and 25, without rotation of the key plug 15 or 1'7, by means of a picking tool inserted through one of the key slots is effectively prevented, because a picking tool having an end portion of suicient length or width to engage the slots 33 and 34 could not be rotated in the key slot suiiciently to `operate the members 23 and 25.

It will also be noted that the lock construction is quite compact, making it ideally suited for use in a knob. This compactness is made possible through the novel arrangement wherein various elements serve dual functions. Thus, the reduced end portions 21 and 22 of the key plugs provide a bearing surface on which the members 23 and 25 may rotate, and also serve as part of the connecting structure for the members 23 and 25. They further serve to prevent picking of the lock through rotation lof the members 23 and 25 by means of a picking tool inserted in the key slots. It should be noted that if the reduced end portions 21 and 22 were eliminated, Ithe lock could be picked in this manner.

The slots 33 and 34 in the members 23 and 25 allow the assembly of the members 23 and 25 on the reduced end portions after the pins 31 and 32 have been inserted through the reduced end portions 21 and 22, and also serve as means engageable by the keys to connect the members 23 and 25 to the key plugs 15 and 17. The members 23 and 25 in addition to forming a part of the latch operating mechanism also serve, in connection with the pins 31 and 32, as a retainer structure for retaining the key plugs 15 and 17 within the cylindrical bores 13 and 14.

While one embodiment of the invention has been shown and described, it will be appreciated that changes and modifications may be made therein without departing from the spirit and scope of .the invention.

We now claim:

1. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, a key slot in each key plug extending axially through each key plug, tumblers for each key plug normally preventing rotation of each key plug but adapted to be set by insertion of a key in the key slot to permit rotation of the key plug, a latch operating mechanism having movable portions positioned `adjacent the inner end of each key plug free to move relatively to said key plug, means interconnecting the movable portions whereby movement of one movable portion effects movement of the other movable portion, said movable portions having means engageable by end portions of a key inserted in the key slot of either of said key plugs whereby rotation of said key with the key plug actuates said latch operating mechanism, said means being off-centered relatively to the Iaxis of rotation of said key plugs and communicating with the key slots of the key plugs only through portions of the key slots which are spaced radially from the axis of rotation of said key plugs whereby a tool inserted through either of said key slots and engaging said means cannot be rotated suiciently to operate said latch operating mechanism without rotation on said key plug.

2. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of reduced diameter, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of each key plug but adapted tto be set by insertion of a key in said key slot to permit rotation vof said key plug, a latch operating member mounted for free rotation on the end portion of reduced diameter of each key plug, means interconnecting said latch operating members whereby rotation tof one latch operating member effects rotation of the other latch operating member, means on each latch operating member providing surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said latch operating member, and means preventing access to said means ton said latch operating member except through a portion of the key slot which is spaced radially from the axis of rotation of the key plug.

3. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of a reduced diameter extending beyond the cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of each key plug but adapted to be set by insertion of a key in said key slot to permit rotation of said key plug, a latch operating member mounted for free rotation on the end portion of reduced diameter of each key plug, means interconnecting said latch operating members whereby rotation of one latch operating member elects rotation of the other latch operating member, an internal groove in each member providing an inturned flange, a pin extending through each of the end portions of reduced diameter of the key plugs and extending within the grooves of said members whereby to connect said members to said end portions of reduced diameter, said members being of slightly larger diameter than said cylinders whereby to retain said key plugs within said cylinders when said members are connected to said end portions of reduced diameter, a pair of diametrically opposed slots through the inturned langes of each of said members whereby to permit passage of the pins into said grooves in said members, and to also provide a slot for engagement of an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said members, said reduced end portions of said key plugs extending across said slots whereby said slots are accessible only through portions of the key slots which are spaced radially from the axis of rotation of the key plugs.

4. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of reduced diameter, a key slot in each key plug extending -axially through the key plug, tumblers for each key plug normally preventing rotation of each key plug but adapted to be set by insertion of a key in said key slot to permit rotation of said key plug, a latch operating member mounted for free rotation on the end portion of reduced diameter of each key plug, means interconnecting said latch operating members whereby rotation of one latch 'operating member eiects rotation of the other latch operating member, an internal groove in each member providing an inturned ange, a pin extending through each of the end portions of reduced diameter of the key plugs and extending within the grooves of said members whereby tio connect said members to said end portions of reduced diameter, a pair of diametrically opposed slots through the inturned flanges of each of said members whereby to permit passage of the pins into said grooves in said members and to also provide a slot for engagement of an end portion of a key inserted in the key `slot whereby rotation of said key with said key plug rotates said member to actuate said latch operating member, said reduced .end portions of said key plug extending across said slots whereby said slots are accessible only through a portion of the key slot which is spaced radially from the axis of rotation of the key plugs.

5. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted .for free rotation adjacent the inner end of each key plug with the gear members :in mesh, means on each gear member providing surfaces for engagement by an end portion of a key inserted in the key slot of one of said key plugs whereby rotation of said key with said key plug rotates said gear member -to actuate said latch operating mechanism, and means preventing access to said means on each gear member except through portions of the key slots which are spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear members lto operate the latch operating mechanism without rotation of the key plugs.

6. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation adjacent the inner end of each key plug with the gear members in mesh, a slot in each gear member which is offset relatively to the axis of rotation of the key plugs and provides surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, and means preventing access to said slots in said gear members except through portions of the key slots which are `spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear members to operate the latch operating mechanism without rotation of said key plugs.

7. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of reduced diameter which extends beyond the inner end of the cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation on the end portion of reduced diameter of each key plug with the gear members in mesh, an internal groove in each gear member providing an inturned ange, a pin extending through the inner end portion of reduced diameter of each key plug and extending within the groove of the gear member behind the internal ange whereby to connect the gear member to the end portion of reduced diameter without preventing rotation of the gear members, a slot through the inturned flange of each of ysaid gear members providing surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, said reduced end portion of each of said key plugs extending across the flanges of said gear p members and preventing access to said slots except through portions of the key slots which are spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear members to operate said latch operating mechanism without rotation of said key plugs.

8. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner' end portion of reduced diameter which extends beyond the inner end of the cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation on the end portion of reduced diameter of each key plug with the gear members in mesh, an internal groove in each gear member providing an inturned ange, a pin extending through the inner end portion of reduced diameter of each key plug and extending within the groove of the gear member behind the inturned ange whereby to connect the gear member to the end portion of reduced diameter, a pair of diametrically disposed slots through the in-turned flanges of each of said gear members whereby to permit passage of the pins into `said grooves in said gear members during assembly of the gear member on said inner end portions of reduced diameter and also providing surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, said reduced end portion of each -of said key plugs extending across the flanges of said gear members and preventing access to said slots except through portions lof the key slots which are spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear members to operate the latch operating mechanism without rotation of said key plugs.

9. In a lock havin-g -two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of reduced diameter which extends beyond the inner end of the cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation on the end portion of reduced diameter of each key plug with the gear members in mesh, an internal groove in each gear member providing an inturned flange, a pin extending through the inner end portion of reduced diameter of each key plug and extending within the groove of the gear member behind the inturned ange whereby to connect the gear member to the end portion of reduced diameter, each gear member being of slightly larger diameter than said cylinders whereby to retain the key plugs within said cylinders when the gear member is connected to the end portion of reduced diameter, a pair of diametrically disposed slots through the inturned anges of each of said gear members whereby to permit passage of the pins into said grooves in said gear members during assembly of the gear member on said inner end portions of reduced diameter and also providing surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, said reduced end portion of each of said key plugs extending across the flanges of said gear members and preventing access to said slots except through portions of the key slots which are spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear members to operate the latch operaing mechanism without rotation of said key plugs.

10. In a lock having two cylinders, a key plug rotatably mounted in each cylinder, each key plug having an inner end portion of reduced diameter which extends beyond the inner end of the cylinder, a key slot in each key plug extending axially through the key plug, tumblers for each key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation on the end portion of reduced diameter of each key plug with the gear members in mesh, means connecting each gear member to the end portion of reduced diameter, each gear member being of slightly larger diameter than said cylinders whereby to retain the key plugs within said cylinders when the gear member is connected to the end portion of reduced diameter, means on said gear members providing surfaces for engagement by an end portion of a key inserted inthe key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, and means preventing access to said means on said gear members except through portions of the key slots which are spaced radially from the axis of rotation of the key plugs whereby to prevent rotation of said gear member without rotation of said key plugs.

1l. In a lock having a cylinder, a key plug rotatably mounted in said cylinder, said key plug having an inner end portion of reduced diameter which extends beyond the inner end of the cylinder, a key slot in said key plug extending axially through the key plug, tumblers for said key plug normally preventing rotation of the key plug but adapted to be set by insertion of a key in said key slot to permit rotation of the key plug, a gear member forming a part of a latch operating mechanism mounted for free rotation on the end portion of reduced diameter of said key plug, an internal groove formed in said gear member providing an inturned ilange, a pin extending through the inner end .portion of reduced diameter o said key plug and extending within the groove of the gear member behind the inturned flange whereby to connect the gear member. to the end portion of reduced diameter, said gear member being of slightly larger diameter than said cylinder whereby to retain the key plug within said cylinder when the gear member is connected to the end portion of reduced diameter, a pair of diametrically disposed slots through the inturned flange of said gear member whereby to permit passage of said pin into said groove in said gear member during assembly of the gear member on said inner end portion of reduced diameter and also providing surfaces for engagement by an end portion of a key inserted in the key slot whereby rotation of said key with said key plug rotates said gear member to actuate said latch operating mechanism, said reduced end portion of said key plug extending across the flange of said gear members and preventing access to said slots except through portions of the key slot which are spaced radially from the axis of rotation of the key plug whereby to prevent rotation of said gear member to operate the latch operating mechanism without rotation of said key plug.

References Cited by the Examiner UNITED STATES PATENTS 474,783 5/ 92 Taylor 70--337' 912,773 2/09 Augenbraun 70-340 X 946,523 1/10 Thomas.

1,046,438 12/ 12 Caldwell.

1,577,335 3/26 Mariotti.

ALBERT H. KAMPE, Primary Examiner. 

2. IN A LOCK HAVING TWO CYLINDERS, A KEY PLUG ROTATABLY MOUNTED IN EACH CYLINDER, EACH KEY PLUG HAVING AN INNER END PORTION OF REDUCED DIAMETER, A KEY SLOT IN EACH KEY PLUG EXTENDING AXIALLY THROUGH THE KEY PLUG, TUMBLERS FOR EACH KEY PLUG NORMALLY PRECENTING ROTATION OF EAHC KEY PLUG BUT ADAPTED TO BE SET BY INSERTION OF A KEY IN SAID KEY SLOT TO PERMIT ROTATION OF SAID KEY PLUG, A LATCH OPERATING MEMBER MOUNTED FOR FREE ROTATION ON THE END PORTION OF REDUCED DIAMETER OF EACH KEY PLUG, MEANS INTERCONNECTING SAID LATCH OPERATING MEMBERS WHEREBY ROTATION OF ONE LATCH OPERATING MEMBERS WHEREBY OF THE OTHER LATCH OPERATING MEMBERS, MEANS ON EACH LATCH OPERATING MEMBER PROVIDING SURFACES FOR ENGAGEMENT BY AN END PORTION OF A KEY INSERTED IN THE KEY SLOT WHEREBY ROTATION OF SAID KEY WITH AID KEY PLUG ROTATES SAID LATCH OPERATING MEMBER, AND MEANS PREVENTING ACCESS TO SAID MEANS ON SAID LATCH OPERATING MEMBER EXCEPT THROUGH A PORTION OF THE KEY SLOT WHICH IS SPACED RADIALLY FROM THE AXIS OF ROTATION OF THE KEY PLUG. 